TiO2/C aerogel composites as high-performance electrode materials for supercapacitors

Abstract

[Formula: see text]/C aerogel composites are primarily composed of resorcinol-formaldehyde (RF) and low-cost commercial titanium dioxide nanoparticles. These composites are synthesized through a simple process of freeze-drying and high-temperature carbonization under inert gas protection. [Formula: see text] nanoparticles in the [Formula: see text]/C aerogel composites produce partial oxygen vacancies by high-temperature treatment under anoxic conditions which is beneficial to increase the carrier density of the material. Electrochemical characterizations confirm the excellent specific capacitance, which reaches a maximum of 250 F [Formula: see text] at a current density of 0.2 A [Formula: see text]. Moreover, after 5000 charge/discharge cycles at a current density of 10 A [Formula: see text], capacitance retention can be up to 98% or more. These properties are attributed to a synergistic effect of electrical double layer capacitance and pseudo-capacitance.